Cable cars are driven by gripping a moving cable commonly positioned beneath the surface of a street and supported for movement in proper position on a series of sheaves or pulley wheels. The later must be maintained in free running condition and for this purpose a team of workmen are required to continuously monitor operation, lubricate wheel bearings and replace malfunctioning cable supporting wheels. The problem is particularly aggravated at street intersections where cable cars are directed around corners and extra loads are accordingly placed on the cable supporting wheels. Despite substantial and continuous attention, existing cable supporting wheel assemblies have had a limited life and must be not only constantly lubricated but removed from the street and replaced--a time consuming and costly operation. A number of different bearing configurations have been proposed for overcoming the foregoing problems, but none to applicant's knowledge have been successful.